Possible Anthropic Support for a Decaying Universe: A Cosmic Doomsday Argument

Abstract

I have suggested that one possible solution of the Boltzmann brain problem is that the universe is decaying at an astronomical rate, making it likely to decay within 20 billion years. A problem with this suggestion is that it seems to require unnatural fine tuning in the decay mechanism that would not be explained anthropically. Here it is pointed out that if a spacetime version of volume averaging were used in the cosmological measure problem, this would give anthropic support for an impending cosmic doomsday.